Experts are on different pages on the ‘ideal’ material to be used for the hull of 36 Water Metro ferries to be operated in Greater Kochi area, even as Kochi Metro Rail Limited (KMRL) has zeroed in on marine-grade steel.
June 29 is the last date to submit tenders for building vessels with steel hull and Fibre Reinforced Plastic (FRP) deck. Another 19 ferries will be introduced at a later stage in the ₹747-crore Water Metro project.
Naval architects say that steel needs least capital expenditure (Capex) and can better withstand impact as compared to vessels that use FRP or aluminium to build the hull. On the flip side, they cite how operational expenses (Opex) will be around 35% more during each vessel’s 25-year lifecycle, mainly since steel is heavier, affecting fuel efficiency.
Lifecycle cost differs
“The lifecycle cost would work out to approximately ₹16 crore for steel, ₹11 crore for FRP and ₹12 crore for an aluminium-hull ferry,” said Sandith Thandasherry who heads the firm that built India’s first solar powered ferry that operates in Alappuzha. The KMRL has not cited the rationale behind selecting steel. The FRP and aluminium are preferred the world over since they enable the vessel to attain speed with less fuel consumption. Moreover, they are more suited to operate on solar power, he said.
“All the nine ferries that the State Water Transport Department would shortly introduce in Kochi would have FRP hull and deck. The department opted for FRP since its fleet of steel vessels was getting corroded fast. Both FRP and aluminium vessels can be as strong as steel if built as per safety norms. There is concern among the naval architect community since the project involves public funds, including a ₹597-crore loan from a German lending agency,” Mr. Thandasherry added.
The head of Ship Technology Department of the Cochin University of Science and Technology, K. Sivaprasad, said that steel vessels are also more prone to repair works, making them dependant more on the manufacturer. They also need more time to manufacture, he said.
Another naval architect Paulson Joseph, who is also an approved consultant for Kerala Inland Vessel Act with Kerala Ports, too said FRP vessels are most operationally efficient. Aluminium hull is better since FRP cannot be recycled. Moreover, aluminium vessels perform almost on par with FRP ones.